Summary of significant accounting policies: (Tables)

12 Months Ended

Dec. 31, 2013

Summary of significant accounting policies:

Schedule of changes in accumulated other comprehensive margin (deficit)

Accumulated Other Comprehensive Margin (Deficit)
		(dollars in thousands)
		Available-for-sale Securities
Balance at December 31, 2010	$	(469	)
Unrealized gain		1,461
(Gain) reclassified to net margin		(374	)
Balance at December 31, 2011		618
Unrealized gain		770
(Gain) reclassified to net margin		(485	)
Balance at December 31, 2012		903
Unrealized (loss)		(1,396	)
(Gain) reclassified to net margin		(56	)
Balance at December 31, 2013	$	(549	)

Schedule of members whose revenues accounted for 10% or more of total operating revenues

	2013		2012		2011
Cobb EMC	13.2	%	12.8	%	12.5	%
Jackson EMC	10.9	%	11.9	%	10.9	%

(1)

None of our other members accounted for 10% or more of our total operating revenues in 2013, 2012 or 2011.

Schedule reflecting details of Asset Retirement Obligations included in balance sheets

		(dollars in thousands)
		2013			2012
Balance at beginning of year	$	381,362		$	298,758
Liabilities incurred		–			1,632
Liabilities settled		(1,392	)		(1,117	)
Accretion		22,900			19,554
Change in Cash Flow Estimates		5,180			62,535
Balance at end of year	$	408,050		$	381,362

Schedule of estimated costs of decommissioning of co-owned nuclear facilities

		(dollars in thousands)
2012 site study		Hatch Unit No. 1		Hatch Unit No. 2		Vogtle Unit No. 1		Vogtle Unit No. 2
Expected start date of decommissioning		2034		2038		2047		2049
Estimated costs based on site study in 2012 dollars	$	186,000	$	252,000	$	182,000	$	241,000

Schedule of annual depreciation rates as approved by Rural Utilities Service

	Range of Useful Life in years*	2013		2012		2011
Steam production	49-65	1.82	%	1.85	%	1.88	%
Nuclear production	37-60	1.54	%	1.54	%	1.45	%
Hydro production	50	2.00	%	2.00	%	2.00	%
Other production	27-33	2.55	%	2.74	%	2.74	%
Transmission	36	2.75	%	2.75	%	2.75	%
General	3-50	2.00-33.33	%	2.00-33.33	%	2.00-33.33	%

*

Calculated based on the composite depreciation rates in effect for 2013.

Schedule of regulatory assets and (liabilities)

		(dollars in thousands)
		2013		2012
Regulatory Assets:
Premium and loss on reacquired debt	$	82,499	$	86,319	(a)
Amortization on capital leases		16,124		28,670	(b)
Outage costs		35,155		30,901	(c)
Interest rate swap termination fees		13,336		17,326	(d)
Asset retirement obligations		–		11,382	(e)
Depreciation expense		48,362		49,785	(f)
Vogtle Units No. 3 and No. 4 training costs		27,678		23,030	(g)
Interest rate options cost		38,984		75,716	(h)
Effects on net margin – Smith Energy Facility		63,491		21,394	(i)
Other regulatory assets		5,479		8,379	(j)
Total Regulatory Assets		331,108		352,902
Regulatory Liabilities:
Accumulated retirement costs for other obligations	$	24,520	$	28,846	(e)
Effects on net margin – Hawk Road Energy Facility		23,379		17,113	(i)
Major maintenance sinking fund		28,064		30,948	(k)
Debt service adder		57,223		47,486	(l)
Asset retirement obligations		19,508		–	(e)
Other regulatory liabilities		6,095		5,592	(j)
Total Regulatory Liabilities		158,789		129,985
Net regulatory assets	$	172,319	$	222,917

(a)

Represents premiums paid, together with unamortized transaction costs related to reacquired debt being amortized over the period of the refunding debt, which range up to 30 years.

(b)

See Note 6 under "Capital Leases." Recovered over the remaining life of the leases through 2031.

(c)

Consists of both coal-fired and nuclear refueling outage costs. Coal-fired outage costs are amortized on a straight-line basis to expense over an 18 to 36-month period. Nuclear refueling outage costs are amortized on a straight-line basis to expense over the 18 to 24-month operating cycles of each unit.

(d)

Represents losses on settled interest rate swaps arrangements that are being amortized through 2016 and 2019.

(e)

See Note 1i under "Asset retirement obligations" for a discussion of the asset retirement obligation deferral and recovery and retirement costs for other obligations.

(f)

Prior to NRC approval of a 20 year license extension for Plant Vogtle, we deferred the difference between Plant Vogtle depreciation expense based on the then 40-year operating license and depreciation expense assuming an expected 20-year license extension. Amortization commenced upon NRC approval of the license extension in 2009 and is being amortized over the remaining life of the plant.

(g)

Deferred charges related to Vogtle Units No. 3 and No. 4 training and interest related carrying costs of such training. Amortization will commence effective with the commercial operation date of each unit and amortized over the life of the units.

(h)

Deferral of net loss associated with the change in fair value of the interest rate options to hedge interest rates on a portion of expected borrowings related to Plant Vogtle Units No.3 and No.4 construction. Amortization will commence effective with the expected principal repayment of the DOE-guaranteed loan and amortized over the expected remaining life of DOE-guaranteed loan which will finance a portion of the construction project.

(i)

Effects on net margin for Smith and Hawk Road Energy Facilities are deferred until the end of 2015 and will be amortized over the remaining life of each plant.

(j)

The amortization periods for other regulatory assets range up to 35 years and the amortization periods of other regulatory liabilities range up to 18 years.

(k)

Represents collections for future major maintenance costs; revenues to be recognized as major maintenance costs are incurred.

(l)

Collections to fund debt payments in excess of depreciation expense through the end of 2025; deferred revenues will be amortized over the remaining useful life of the plants.

Schedule of components of other income

		(dollars in thousands)
		2013			2012		2011
Capital credits from associated companies (Note 4)	$	1,954		$	1,919	$	2,095
Net revenue from Georgia Transmission and Georgia System Operations for shared Administrative and General costs		4,459			4,280		4,071
Miscellaneous other		(723	)		214		38
Total	$	5,690		$	6,413	$	6,204